sv_main.c

Quake 2 Source code for students by Theerthan You can also download from idsoftwares.com

/*
Copyright (C) 1997-2001 Id Software, Inc.

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  

See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

*/

#include "server.h"

netadr_t	master_adr[MAX_MASTERS];	// address of group servers

client_t	*sv_client;			// current client

cvar_t	*sv_paused;
cvar_t	*sv_timedemo;

cvar_t	*sv_enforcetime;

cvar_t	*timeout;				// seconds without any message
cvar_t	*zombietime;			// seconds to sink messages after disconnect

cvar_t	*rcon_password;			// password for remote server commands

cvar_t	*allow_download;
cvar_t *allow_download_players;
cvar_t *allow_download_models;
cvar_t *allow_download_sounds;
cvar_t *allow_download_maps;

cvar_t *sv_airaccelerate;

cvar_t	*sv_noreload;			// don't reload level state when reentering

cvar_t	*maxclients;			// FIXME: rename sv_maxclients
cvar_t	*sv_showclamp;

cvar_t	*hostname;
cvar_t	*public_server;			// should heartbeats be sent

cvar_t	*sv_reconnect_limit;	// minimum seconds between connect messages

void Master_Shutdown (void);


//============================================================================


/*
=====================
SV_DropClient

Called when the player is totally leaving the server, either willingly
or unwillingly.  This is NOT called if the entire server is quiting
or crashing.
=====================
*/
void SV_DropClient (client_t *drop)
{
	// add the disconnect
	MSG_WriteByte (&drop->netchan.message, svc_disconnect);

	if (drop->state == cs_spawned)
	{
		// call the prog function for removing a client
		// this will remove the body, among other things
		ge->ClientDisconnect (drop->edict);
	}

	if (drop->download)
	{
		FS_FreeFile (drop->download);
		drop->download = NULL;
	}

	drop->state = cs_zombie;		// become free in a few seconds
	drop->name[0] = 0;
}



/*
==============================================================================

CONNECTIONLESS COMMANDS

==============================================================================
*/

/*
===============
SV_StatusString

Builds the string that is sent as heartbeats and status replies
===============
*/
char	*SV_StatusString (void)
{
	char	player[1024];
	static char	status[MAX_MSGLEN - 16];
	int		i;
	client_t	*cl;
	int		statusLength;
	int		playerLength;

	strcpy (status, Cvar_Serverinfo());
	strcat (status, "\n");
	statusLength = strlen(status);

	for (i=0 ; i<maxclients->value ; i++)
	{
		cl = &svs.clients[i];
		if (cl->state == cs_connected || cl->state == cs_spawned )
		{
			Com_sprintf (player, sizeof(player), "%i %i \"%s\"\n", 
				cl->edict->client->ps.stats[STAT_FRAGS], cl->ping, cl->name);
			playerLength = strlen(player);
			if (statusLength + playerLength >= sizeof(status) )
				break;		// can't hold any more
			strcpy (status + statusLength, player);
			statusLength += playerLength;
		}
	}

	return status;
}

/*
================
SVC_Status

Responds with all the info that qplug or qspy can see
================
*/
void SVC_Status (void)
{
	Netchan_OutOfBandPrint (NS_SERVER, net_from, "print\n%s", SV_StatusString());
#if 0
	Com_BeginRedirect (RD_PACKET, sv_outputbuf, SV_OUTPUTBUF_LENGTH, SV_FlushRedirect);
	Com_Printf (SV_StatusString());
	Com_EndRedirect ();
#endif
}

/*
================
SVC_Ack

================
*/
void SVC_Ack (void)
{
	Com_Printf ("Ping acknowledge from %s\n", NET_AdrToString(net_from));
}

/*
================
SVC_Info

Responds with short info for broadcast scans
The second parameter should be the current protocol version number.
================
*/
void SVC_Info (void)
{
	char	string[64];
	int		i, count;
	int		version;

	if (maxclients->value == 1)
		return;		// ignore in single player

	version = atoi (Cmd_Argv(1));

	if (version != PROTOCOL_VERSION)
		Com_sprintf (string, sizeof(string), "%s: wrong version\n", hostname->string, sizeof(string));
	else
	{
		count = 0;
		for (i=0 ; i<maxclients->value ; i++)
			if (svs.clients[i].state >= cs_connected)
				count++;

		Com_sprintf (string, sizeof(string), "%16s %8s %2i/%2i\n", hostname->string, sv.name, count, (int)maxclients->value);
	}

	Netchan_OutOfBandPrint (NS_SERVER, net_from, "info\n%s", string);
}

/*
================
SVC_Ping

Just responds with an acknowledgement
================
*/
void SVC_Ping (void)
{
	Netchan_OutOfBandPrint (NS_SERVER, net_from, "ack");
}


/*
=================
SVC_GetChallenge

Returns a challenge number that can be used
in a subsequent client_connect command.
We do this to prevent denial of service attacks that
flood the server with invalid connection IPs.  With a
challenge, they must give a valid IP address.
=================
*/
void SVC_GetChallenge (void)
{
	int		i;
	int		oldest;
	int		oldestTime;

	oldest = 0;
	oldestTime = 0x7fffffff;

	// see if we already have a challenge for this ip
	for (i = 0 ; i < MAX_CHALLENGES ; i++)
	{
		if (NET_CompareBaseAdr (net_from, svs.challenges[i].adr))
			break;
		if (svs.challenges[i].time < oldestTime)
		{
			oldestTime = svs.challenges[i].time;
			oldest = i;
		}
	}

	if (i == MAX_CHALLENGES)
	{
		// overwrite the oldest
		svs.challenges[oldest].challenge = rand() & 0x7fff;
		svs.challenges[oldest].adr = net_from;
		svs.challenges[oldest].time = curtime;
		i = oldest;
	}

	// send it back
	Netchan_OutOfBandPrint (NS_SERVER, net_from, "challenge %i", svs.challenges[i].challenge);
}

/*
==================
SVC_DirectConnect

A connection request that did not come from the master
==================
*/
void SVC_DirectConnect (void)
{
	char		userinfo[MAX_INFO_STRING];
	netadr_t	adr;
	int			i;
	client_t	*cl, *newcl;
	client_t	temp;
	edict_t		*ent;
	int			edictnum;
	int			version;
	int			qport;
	int			challenge;

	adr = net_from;

	Com_DPrintf ("SVC_DirectConnect ()\n");

	version = atoi(Cmd_Argv(1));
	if (version != PROTOCOL_VERSION)
	{
		Netchan_OutOfBandPrint (NS_SERVER, adr, "print\nServer is version %4.2f.\n", VERSION);
		Com_DPrintf ("    rejected connect from version %i\n", version);
		return;
	}

	qport = atoi(Cmd_Argv(2));

	challenge = atoi(Cmd_Argv(3));

	strncpy (userinfo, Cmd_Argv(4), sizeof(userinfo)-1);
	userinfo[sizeof(userinfo) - 1] = 0;

	// force the IP key/value pair so the game can filter based on ip
	Info_SetValueForKey (userinfo, "ip", NET_AdrToString(net_from));

	// attractloop servers are ONLY for local clients
	if (sv.attractloop)
	{
		if (!NET_IsLocalAddress (adr))
		{
			Com_Printf ("Remote connect in attract loop.  Ignored.\n");
			Netchan_OutOfBandPrint (NS_SERVER, adr, "print\nConnection refused.\n");
			return;
		}
	}

	// see if the challenge is valid
	if (!NET_IsLocalAddress (adr))
	{
		for (i=0 ; i<MAX_CHALLENGES ; i++)
		{
			if (NET_CompareBaseAdr (net_from, svs.challenges[i].adr))
			{
				if (challenge == svs.challenges[i].challenge)
					break;		// good
				Netchan_OutOfBandPrint (NS_SERVER, adr, "print\nBad challenge.\n");
				return;
			}
		}
		if (i == MAX_CHALLENGES)
		{
			Netchan_OutOfBandPrint (NS_SERVER, adr, "print\nNo challenge for address.\n");
			return;
		}
	}

	newcl = &temp;
	memset (newcl, 0, sizeof(client_t));

	// if there is already a slot for this ip, reuse it
	for (i=0,cl=svs.clients ; i<maxclients->value ; i++,cl++)
	{
		if (cl->state == cs_free)
			continue;
		if (NET_CompareBaseAdr (adr, cl->netchan.remote_address)
			&& ( cl->netchan.qport == qport 
			|| adr.port == cl->netchan.remote_address.port ) )
		{
			if (!NET_IsLocalAddress (adr) && (svs.realtime - cl->lastconnect) < ((int)sv_reconnect_limit->value * 1000))
			{
				Com_DPrintf ("%s:reconnect rejected : too soon\n", NET_AdrToString (adr));
				return;
			}
			Com_Printf ("%s:reconnect\n", NET_AdrToString (adr));
			newcl = cl;
			goto gotnewcl;
		}
	}

	// find a client slot
	newcl = NULL;
	for (i=0,cl=svs.clients ; i<maxclients->value ; i++,cl++)
	{
		if (cl->state == cs_free)
		{
			newcl = cl;
			break;
		}
	}
	if (!newcl)
	{
		Netchan_OutOfBandPrint (NS_SERVER, adr, "print\nServer is full.\n");
		Com_DPrintf ("Rejected a connection.\n");
		return;
	}

gotnewcl:	
	// build a new connection
	// accept the new client
	// this is the only place a client_t is ever initialized
	*newcl = temp;
	sv_client = newcl;
	edictnum = (newcl-svs.clients)+1;
	ent = EDICT_NUM(edictnum);
	newcl->edict = ent;
	newcl->challenge = challenge; // save challenge for checksumming

	// get the game a chance to reject this connection or modify the userinfo
	if (!(ge->ClientConnect (ent, userinfo)))
	{
		if (*Info_ValueForKey (userinfo, "rejmsg")) 
			Netchan_OutOfBandPrint (NS_SERVER, adr, "print\n%s\nConnection refused.\n",  
				Info_ValueForKey (userinfo, "rejmsg"));
		else
			Netchan_OutOfBandPrint (NS_SERVER, adr, "print\nConnection refused.\n" );
		Com_DPrintf ("Game rejected a connection.\n");
		return;
	}

	// parse some info from the info strings
	strncpy (newcl->userinfo, userinfo, sizeof(newcl->userinfo)-1);
	SV_UserinfoChanged (newcl);

	// send the connect packet to the client
	Netchan_OutOfBandPrint (NS_SERVER, adr, "client_connect");

	Netchan_Setup (NS_SERVER, &newcl->netchan , adr, qport);

	newcl->state = cs_connected;
	
	SZ_Init (&newcl->datagram, newcl->datagram_buf, sizeof(newcl->datagram_buf) );
	newcl->datagram.allowoverflow = true;
	newcl->lastmessage = svs.realtime;	// don't timeout
	newcl->lastconnect = svs.realtime;
}

int Rcon_Validate (void)
{
	if (!strlen (rcon_password->string))
		return 0;

	if (strcmp (Cmd_Argv(1), rcon_password->string) )
		return 0;

	return 1;
}

/*
===============
SVC_RemoteCommand

A client issued an rcon command.
Shift down the remaining args
Redirect all printfs
===============
*/
void SVC_RemoteCommand (void)
{
	int		i;
	char	remaining[1024];

	i = Rcon_Validate ();

	if (i == 0)
		Com_Printf ("Bad rcon from %s:\n%s\n", NET_AdrToString (net_from), net_message.data+4);
	else
		Com_Printf ("Rcon from %s:\n%s\n", NET_AdrToString (net_from), net_message.data+4);

	Com_BeginRedirect (RD_PACKET, sv_outputbuf, SV_OUTPUTBUF_LENGTH, SV_FlushRedirect);

	if (!Rcon_Validate ())
	{
		Com_Printf ("Bad rcon_password.\n");
	}
	else
	{
		remaining[0] = 0;

		for (i=2 ; i<Cmd_Argc() ; i++)
		{
			strcat (remaining, Cmd_Argv(i) );
			strcat (remaining, " ");
		}

		Cmd_ExecuteString (remaining);
	}

	Com_EndRedirect ();
}

/*
=================
SV_ConnectionlessPacket

A connectionless packet has four leading 0xff
characters to distinguish it from a game channel.
Clients that are in the game can still send
connectionless packets.
=================
*/
void SV_ConnectionlessPacket (void)
{
	char	*s;
	char	*c;

	MSG_BeginReading (&net_message);
	MSG_ReadLong (&net_message);		// skip the -1 marker

	s = MSG_ReadStringLine (&net_message);

	Cmd_TokenizeString (s, false);

	c = Cmd_Argv(0);
	Com_DPrintf ("Packet %s : %s\n", NET_AdrToString(net_from), c);

	if (!strcmp(c, "ping"))
		SVC_Ping ();
	else if (!strcmp(c, "ack"))
		SVC_Ack ();
	else if (!strcmp(c,"status"))
		SVC_Status ();
	else if (!strcmp(c,"info"))
		SVC_Info ();
	else if (!strcmp(c,"getchallenge"))
		SVC_GetChallenge ();
	else if (!strcmp(c,"connect"))
		SVC_DirectConnect ();
	else if (!strcmp(c, "rcon"))
		SVC_RemoteCommand ();
	else
		Com_Printf ("bad connectionless packet from %s:\n%s\n"
		, NET_AdrToString (net_from), s);
}


//============================================================================

/*
===================
SV_CalcPings

Updates the cl->ping variables
===================
*/
void SV_CalcPings (void)
{
	int			i, j;
	client_t	*cl;
	int			total, count;

	for (i=0 ; i<maxclients->value ; i++)
	{
		cl = &svs.clients[i];
		if (cl->state != cs_spawned )